I am still quite a noob, but i think the deck has a bit too much defense. Maybe swap out the Ivana for a Stop ability that affects your life or your opponent's life. The Stop -dmg seems to be pretty useless when most of the deck lowers damage.
I think ivana is right where she should be since most other cards are vulnerable to soa, I personally think that pussycats + sakrohm dr is a lot based on you drawing and winning with sigma and reducing the dmg you receive, too much damage reduction for my taste, all revolving around a poison. I would go the sakrohm half( with na boh instead of nimestiec) and half gheist/roots/nightmare/piranas with big dmg dealers.